Biomedical subjects

J D Padayatty

Publications and source records attributed to J D Padayatty.

At least 19 recordsLinked to original sources

PubMed1992

Nucleotide sequence of the cDNA and the derived amino acid sequence for the major antigenic protein of foot and mouth disease virus, type Asia 1 63/72.

A 0.9 kb cDNA for the foot and mouth disease virus (FMDV) type Asia 1 63/72, cloned in the plasmid pUR222 by dC/dG tailing method, was expressed into a protein which was immunogenic in guinea pigs and cattle. The protein purified to homogeneity was found to be basic and of 38 kDa. A sequence of 879 nucleotides of the inserted cDNA was obtained. The nucleotide sequence was 65% GC-rich and was homologous to the gene for VPI of FMDV types A5, OIK and C3 to the extent of 35-40%. From the nucleotide sequence, a sequence of 293 amino acids was derived which contained 43 arginine, 4 lysine, 7 glutamic acid and 18 aspartic acid residues making the protein highly basic. The molecular weight was calculated to be 31.6 kDa. The 38 kDa protein produced by the cloned cDNA is a fused protein composed of the 293 amino acids; 5 and 55 amino acids of the alpha-complementation protein of the beta-galactosidase at the N and C terminal, respectively, and 5 amino acid coded by the dG/dC tails used for cloning the cDNA.

Amino Acid Sequence↗

PubMed1992

Characterization and immune response of a protein produced by a cDNA clone of foot and mouth disease virus, type Asia 1 63/72.

A 0.9 kb double stranded cDNA of foot and mouth disease virus (FMDV) Type Asia 1, 63/72 was cloned in an expression vector, pUR222. A protein of 38 kd was produced by the clone which reacted with the antibodies raised against the virus. A 20 kd protein which may be derived from the 38 kd protein contained the antigenic epitopes of the protein VP1 of the virus. Injection of 10-20 micrograms of the partially purified 38 and 20 kd proteins or a lysate of cells containing 240 micrograms of the proteins elicited high titers of FMDV specific antibodies in guinea pigs and cattle respectively. Also, at these concentrations, the proteins protected 5 of 8 guinea pigs and 3 of 8 cattle when challenged with a virulent virus.

Animals↗

PubMed1990

Structure of colitis phage lytic enzyme gene.

A sequence of 163 amino acids was derived from the nucleotide sequence of a DNA fragment bearing the colitis phage lytic enzyme gene. The molecular weight, basicity and the sequence of the three N-terminal amino acids agreed with those of the phage lytic enzyme. The amino acids at the N-terminal of the colitis phage enzyme are homologous with those of T4, P22 and phi 29 phage lysozymes, to the extent of 18-34%. The transcription initiation site was mapped at 166 nucleotides upstream to the translation initiation codon, ATG. The Shine-Dalgarno sequence, the Pribnow box and the RNA polymerase recognition site were at 5.10 and 35 nucleotdies respectively, upstream to the transcription initiation site. The transcription termination signal, (the inverted repeat) and the termination site (the oligo TS) were at 7 and 28 nucleotides respectively, downstream to the translation termination site, TAA.

Amino Acid Sequence↗

PubMed1989

Initiation of transcription of rDNA in rice.

Three direct repeats of 320, 340 and 238 nucleotides were detected upstream to the 5' end of the 18S rRNA gene of an rDNA unit present on a 9.8 kb EcoRI fragment of the rice DNA. The primer extension analysis showed that the site of initiation of transcription is in the 1st repeat at an A, the 623rd nucleotide upstream to the 5' end of the 18S rRNA gene. Different stretches of the intergenic spacer DNA linked to the Chloramphenicol acetyl transferase gene were transcribed in the intact nuclei of rice embryos. The S1 nuclease protection analysis of the transcripts using [32P]-labelled Chloramphenicol acetyl transferase gene as the probe showed the presence of multiple promoters for rDNA transcription.

Animals↗

PubMed1989

A minor 9.8 kb rDNA unit of rice variety IR-20.

A clone bearing a 9.8 kb EcoRI fragment of rice DNA containing the genes for the rRNAs and the intergenic spacer was identified by screening a rice genomic library in lambda Charon 4 phage with rRNAs. The 9.8 kb EcoRIDNA fragment was found to be a minor rDNA unit of rice variety IR-20. The rRNA genes and the intergenic spacer were mapped by hybridization and nucleotide sequence analyses. The DNAs in the intergenic spacer of the minor rDNA unit of 9.8 kb and the major rDNA unit of 8.9 kb cross-hybridized showing that those regions are homologous.

Base Sequence↗

PubMed1988

Putative termination sites for rDNA transcription in rice.

A clone bearing a 9.8 kb insert DNA containing the rDNA unit was identified by screening an EcoR1 library of rice DNA in lambda Charon 4 phage with [32P]-rRNAs. The S1 nuclease mapping of the rDNA-precursor rRNA hybrids showed the presence of two transcription termini on the rDNA. They were mapped at positions 616 and 620 nucleotides downstream to the end of the 25S rRNA gene. The 18 nucleotide sequence, where the transcription terminates on the rDNA in rice and mice are homologous albeit in the reverse orientation.

Base Sequence↗

PubMed1988

Identification and expression of the 20 kd structural protein gene of colitis bacteriophage.

The 2.3 kb BamHI fragment from the colitis bacteriophage DNA was transcribed and translated into a 20 kd structural protein P6, in a coupled transcription-translation system derived from Escherichia coli. This protein was expressed in vivo by the 2.3 kb DNA cloned in pBR322. The gene with the regulatory elements for this protein was located on the 680 bp AvaII fragment of the insert DNA. It hybridized with two RNAs of sizes 520 and 1630 nucleotides indicating that both are messengers for the 20 kd protein. Dot-blot hybridization showed that the transcripts for P6 reached a maximum level at 12 min after phage infection.

Chromosome Mapping↗

PubMed1987